To determine if insulin resistance or obesity is associated with plasma lipid response to egg consumption, 201 subjects will be divided into three equal groups, lean insulin sensitive, lean insulin resistant, and obese insulin resistant, using an insulin sensitivity index < or > 7.0 determined by a frequently sampled IV glucose tolerance test and BMI > or < 27.5 kg/m2. Subjects will be recruited from institutional personnel and public advertising, taught the NCEP Step I (moderately low fat) diet and fed in a double-blind cross-over design pasteurized whole egg and/or egg substitute in three randomized monthly protocols at levels of 0, 2 or 4 eggs daily, separated by one month washout periods. The effect of egg feeding will be assessed by changes in LDL-cholesterol, and also by changes in HDL-cholesterol, apoprotein B and density gradient vertical analytical profiles of the lipoprotein pattern.